How to prove there is a ground rod

Not when using a simple multimeter.

You might be able to use a clamp-on style ground resistance meter to show the rod is interconnected to other grounding paths, but you likely wont get a specific ohmic value.
 
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Others correct me if I am wrong, but the only way to prove there is a ground rod is to see it. You can use a fall of potential meter to prove you have a measured value to ground, thereby proving the wire you are checking is continuous with ground but that is all.
 
Strathead said:
Others correct me if I am wrong, but the only way to prove there is a ground rod is to see it. You can use a fall of potential meter to prove you have a measured value to ground, thereby proving the wire you are checking is continuous with ground but that is all.
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There is no blanket requirement in the code for a ground rod, the 'home inspector' should just be inspecting to 250.50
 
infinity said:
Short answer no. Testing will not tell you if there is a ground rod or not.
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So if I see a wire coming out of the ground and going to the service grounded conductor or another part of the GES, and I disconnect it, and do a ground resistance test on it, and it comes back 500 ohms (which I gather would be on the high side for a ground rod), is it plausible that it's just a bare wire disappearing into the ground, with no grounding electrode connected underground?

Cheers, Wayne
 
wwhitney said:
So if I see a wire coming out of the ground and going to the service grounded conductor or another part of the GES, and I disconnect it, and do a ground resistance test on it, and it comes back 500 ohms (which I gather would be on the high side for a ground rod), is it plausible that it's just a bare wire disappearing into the ground, with no grounding electrode connected underground?
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Plausible is proof of nothing which is the OP's question. Yes it's plausible that the rod doesn't exist but you still cannot prove it one way or another. Even if the test said it was 20 Ω that wouldn't prove that the rod exists either.
 
infinity said:
Plausible is proof of nothing which is the OP's question. Yes it's plausible that the rod doesn't exist but you still cannot prove it one way or another. Even if the test said it was 20 Ω that wouldn't prove that the rod exists either.
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I agree that you can't say there's a rod, there could be a plate or pipe electrode. But I don't think you can get 20 ohms to remote earth just by sticking a copper wire in the ground, so that would be proof that some electrode exists.

Cheers, Wayne
 
I have used the clamp-on testers to verify builfing steel connections to grounding rings/ground electrodes. An incomplete circuit, like an unterminated buried wire, would show up as an anomaly when compared to other electrode connections.

Still not absolute proof of a rod.
 
Is this a “home inspector” like realtors hire before a home gets sold? If so, they have zero authority, are of dubious value, and I have yet to meet one who would make it as a first year apprentice. I generally have zero respect for those people.

Second, if there is an inspection label on the panel, that means it was inspected at the time of install and passed by the AHJ, who *does* have authority.

Last, every panel change I do gets 2 new ground rods, and water and gas bonding, usually on the exterior. It’s far easier, for me, to just install all new, rather than trying to test/prove that it’s existing.
 
Seven-Delta-FortyOne said:
Is this a “home inspector” like realtors hire before a home gets sold? If so, they have zero authority, are of dubious value, and I have yet to meet one who would make it as a first year apprentice. I generally have zero respect for those people.
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You must of read the electrical portion of the last inspection I had done on my current dwelling. 🙄

Second, if there is an inspection label on the panel, that means it was inspected at the time of install and passed by the AHJ, who *does* have authority.
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Yep, that should be good enough.
 
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